Fluid pressure generator



June 1, 1954 B. M. THUN FLUID PRESSURE GENERATOR 4 Sheets-Sheet 1 Filed April 22, 1949 IN VENT OR.

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FLUID PRESSURE GENEIIRATOR 4 Sheets-Sheet 3 JfIZornEI S June 1, 1954 THUN 2,679,808

FLUID PRESSURE GENERATOR Filed April 22, 1949 4 Sheets-Sheet 4 Fig. 7

INVENTOR. BemA/w 77?. M *M flfiorneyy Patented June 1, 1.954

UNITED STATES PATENT OFFICE FLUID PRESSURE GENERATOR Bernard M. Thun, Milwaukee, Wis.

Application April 22, 1949, Serial No. 88,982

9 Claims.

This invention relates to piston-type fluid pumps and particularly to ultra-high pressure radial fluid power generators and to the method of making the same.

The invention provides a radial plunger-type pump in which the crankcase, cylinder bores, fluid intake and high pressure discharge manifolds are formed in a single cast structure providing a pump of rugged construction and light weight.

An object of the invention is to reduce the number of cast members comprising the pump body for greater simplicity of construction and reduction in the required number of gaskets therebetween.

Another object is to provide the high pressure passages of the pump in a single casting.

Another object is to eliminate the possibility of distortion of the pump body because of loosened or over-tightened assembly bolts.

Another object is to provide a pump of the class described which requires a minimum number of and smaller high-pressure sealing gaskets.

Another object is to provide a better means for returning the pump plungers inwardly during operation of the pump.

Another object is to provide for the replacement of all of the high pressure sealing means without disassembly of the pump itself or of the pump from the line.

Another object is to provide for the replacement of any of the valves of the pump without disassembly of the same or of the pump from the line.

Another object is to provide a novel method of manufacture of a radial pump body which includes the cylinder bores, the fluid intake and discharge manifolds.

Another object is to reduce the cost of manufacture of pumps of the class described.

Another object is to more positively ensure the accuracy of the cross-section of the high pressure passages and allow for slight mislocations of the cores in casting.

Another object is to provide smooth cored highpressure passages within the pump casting of controlled cross-section or area to reduce frictional and eddy current losses.

Another object is to eliminate air pockets in the fluid circuit of the pump and assure instant pump operation upon rotation of the pump shaft.

These and other objects and advantages will be more fully set forth in the following description of a preferred embodiment of the invention illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a rear end elevation of the pump;

Fig. 2 is a front end elevation of the pump;

Fig. 3 is a transverse vertical sectional view of the pump taken on line 3-3 of Fig. 1;

Fig. 4 is a plan view showing the manifold liner and supporting assembly;

Fig. 5 is an end elevation of the assembly shown in Fig. 4;

Fig. 6 is a cross-sectional view taken on line fili of Fi 3;

Fig. 7 is a cross-sectional view taken on line l-'l of Fig. 3;

Fig. 8 is a front elevation of an alternate construction of the operating plunger return ring partially broken away and sectioned and one plunger operatively associated therewith; and

Fig. 9 is a side elevation of the plunger and ring in section.

The pump shown in the drawings comprises the pump housing I, the mounting base cover 2 closing and supporting housing I, the operating shaft 3, and the reciprocating plungers 4.

Housing i, comprising a single casting, as will be described, carries the inner end of shaft 3 in the bearing 5, and the plungers :1 in the series of cylinder bores 6 arranged radially of the cocentric 1 of shaft 3. The intake 8 at the forward end of housing I is threaded to receive a pipe, not shown, and communicates with the circular interior chamber 9 forwardly of the pump through the channels it formed in the body of the housing and passing on the outside of bearing 5.

The outer bearing race H is carried by the r rollers E2 on eccentric f of shaft 3 to engage the larger flat shoulder 13 or end of each of plungers t and effect the outward pump stroke. The ring I4, moving with bearing ll, effects the return stroke of each of plungers l, as will be described. The rear edge of ring l4, disposed within char ber 9 around bearing ll, enters the transverse slots l5 in the forward side of each of the lower end of plungers l projecting into chamber 9.

The raised circular face it of cover 2 fits within the open rear end of housing I to close chamher 9 formed therein and engages the opposite end of ring Hi to prevent disengagement of ring I4 and plunger 4.

The extending flanges I! are formed integrally with cover 2 and are provided with holes is for mounting the pump. The radial double-row ball bearing 19 mounted within cover 2 carries the forward end of shaft 3 which is splined as at 20 to receive the spacer collar 2i and a gear or pulley, not shown.

The passages 22 open at the base of the plungers opposite slots 5 into chamber 9 to receive the fluid therefrom and extend the length of the plungers to the upper part of the cylinders 6 to deliver the fluid thereto for pumping.

The lower and upper check valves 23 and 24, respectively, are retained within intake passages 22 by the snap rings 25 and are disposed to close the respective passages 22 and prevent the return of fluid to chamber 9 during the outward stroke of the respective plunger.

The circular passage 26 within the body of housing comprises the discharge manifold into which the pumped fluid passes for delivery at high pressure to the outlet port 27 in the side of housing and threaded to receive a pipe, not shown.

The passage 29 extending axially and rearwardly of the pump from the upper end of each cylinder 6 receives the fluid under pressure therefrom. Each passage 28 carries the valve unit 29 which is arranged to deliver the fluid to manifold passage 26 through the radial passage 30 and which prevents the fluid return during the return stroke of plunger 4.

The valve unit 29 comprises the cylindrical valve body 3| carrying the ball check 32 and the spring 33 seating ball check 32 and being retained by the adjustable screw plug 34.

Housing I comprises a single sand casting having a central cored opening extending axially through the housing to provide the chamber 9 at its larger end and the intake port 8 at its smaller end. The ribs 35 radially arranged near the intake end of chamber 9 are machined after casting to carry bearing 5 and provide the channels Ill.

The outer end of each machined bore 36 is threaded as at 31 to receive the plug 38 and the gasket 39 to close the bore and comprise the cylinder 6 to receive a plunger 4.

The circular metal hollow liner 40, with the pipes 4| which project radially thereof and are closed by the plugs 42, is supported by the several projecting pipe extensions 43 and is cast well within the body of housing about the center cored chamber 9 and with each pipe 4| extending in the direction of or parallel to a corresponding cylinder bore 36.

The passages 28 are formed by drilling from the rear end of housing I into each cylinder 6 beneath plug 38 and are reduced near the forward end to provide the shoulders 44. Pipes 4|, disposed within the casting, as described, project into the cutting radius of the drill, not shown, forming the passages 28 so that the drill cuts away plugs 42 and the pipe supports 43 and opens pipes 4| and liner 4!). The outer end of each passage 28 is then threaded as at 46 to receive the plug 4! which secures valve unit 29 within passage 28. The gasket ring 48 is disposed between the inner end of the valve body 3| of each unit 29 and shoulder 44 to prevent by-passing of the fluid under pressure around the valve unit. The gasket ring 49 between the valve body 3| and each plug 41 closes the outer end of passage 28 to prevent loss of fluid. Gaskets 48 and 49 preferably comprise soft copper washers capable on tightening of plug 4'! of cold flow outwardly to engage the wall of passage 28.

Outlet 21 of the pump is formed by drilling into the circular liner 49 from either the front of housing or from the side, as shown in the drawmgs.

Liner preferably comprises a tubular steel member bent to circular form with the ends in substantial alignment and joined.

In the operation of the pump, plungers 4 are reciprocated by eccentric 'l of shaft 3 and ring M. In the outward stroke the bearing race II on eccentric 1 makes a line contact with the lower shoulder 3 of the respective plungers 4 which line extends the full width of the shoulder and moves laterally with respect thereto as bearing race gyrates on the eccentric. The return stroke is effected by ring M which is maintained in fixed relation to bearing race II by the several plungers 4. The lower face of each slot I5 is curved slightly to allow a corresponding gyratory motion of ring I4. The face of ring 4 is supported against the flat face N3 of cover 2 and is in sliding contact therewith over its entire circumference for maximum bearing surface and a minimum of wear.

If desired, ring l4 and the bearing race Il may be formed integrally and comprise the single ring 50 shown in Figs. 8 and 9.

In assembling the pump, plungers 4, ring l4 and bearing 5 are assembled within housing prior to securing cover 2 which closes chamber 9 and carries the bearings I9 and the flange-type oil seal 5| engaging collar 2| to protect the bearmgs.

The number of cap screws 52 which secure cover 2 to the rear face of housing I are circularly arranged to extend into housing between cylinders 6 and to allow assembly of housing and cover 2 in the same number of relative positions on the axis of shaft 3 to disposed outlet 21 in the required position with respect to the mounting flanges l1.

Housing including manifold or header 26, comprises a solid casting which may be secured to cover 2 without distortion and is capable of withstanding severe shocks and rough handling.

The pump is inexpensive and easily manufactured. The entire high-pressure hydraulic circuit of the pump is disposed within the cast body of housing and accordingly does not cross parting lines which requires large gasket-type seals. The three rings 39, 48 and 49 for each cylinder 6 are individually replaceable and constitute the entire high-pressure gasket seals required for the pump.

Intake valves 23 and 24 and discharge valves 29 are individually accessible for inspection or replacement without disassembly of the entire pump.

Cover member 2 may be removed with shaft 3 from housing for inspection of ring l4 without disassembly of the valves and other parts of the pump. The entire ring is evenly supported by face It of cover 2 in slots |5 providing nominal frictional losses and wear.

Various embodiments of the invention may be employed within the scope of the accompanying claims.

I claim:

1. A pump of the class described comprising a unitary cast housing having a central cored opening therethrough one end of which provides a fluid intake opening, a cover member secured to said housing and closing the other end thereof, a shaft journally carried by said cover and housing and having an eccentric disposed within said opening, a series of hollow plungers operatively engaging said shaft eccentric and disposed to reciprocate in radially arranged cylinder bores opening outwardly of said housing, valve means within said plungers admitting fluid to said cylinder bores from said intake opening, a chamber formed within said housing encircling said cored opening, recesses opening rearwardly of said housing and forwardly into the respective cylinder bores and communicating intermediately with said chamber, valve means disposed within each of said recesses controlling the discharge of fluid therethrough from the cylinder bore into said chamber, and threaded closure members closing the outer ends of the cylinder bores of said housing and said recesses.

2. A pump of the class described comprising a unitary cast housing having a central cored opening therethrough one end of which provides a fluid intake opening, a cover member secured to said housing and closing the other end thereof, a shaft journally carried by said cover and said housing having an eccentric disposed within said opening, a series of hollow plungers operatively engaging said shaft eccentric and disposed to reciprocate in radially arranged cylinder bores opening outwardly of said housing, valve means within said plungers admitting fluid to said cylinder bores from said intake opening, a series of enlarged recesses opening rearwardly of said housing and communicating with a corresponding series of discharge passages extending forwardly into said cylinder bores, valve means disposed within said recesses controlling the discharge of said plungers, and closure members threaded within said housing sealing the outer ends of said bores and recesses.

3. A pump of the class described comprising a unitary cast housing having a central cored opening therethrough one end of which provides a fluid intake opening, a cover member secured to said housing and closing the other end thereof, a shaft journally carried by said cover and said housing having an eccentric disposed within said opening, a series of hollow plungers operatively engaging said shaft eccentric and disposed to reciprocate in radially arranged cylinder bores opening outwardly of said housing, valve means within said plungers admitting fluid to said cylinder bores from said intake opening, a series of enlarged recesses opening rearwardly of said housing and communicating with a corresponding series of discharge passages extending forwardly into said cylinder bores, valve means disposed within said recesses controlling the discharge of said plungers, and closure members threaded within said housing sealing the outer ends of said bores and recesses, said closure members being individually removable and providing access to the respective valve means for replacement thereof.

4:. A high pressure pump of the class described comprising a single integral cast metal pump body devoid of parting lines and having a central bore adapted at one end to provide an inlet passage for the pump, a plurality of radially disposed bores in said body arranged in circumferentially spaced relation in a plane normal to the axis of said central bore and constituting individual cylinders, corresponding pump plungers reciprocable in said cylinders of a type passing fluid from said inlet to the outer end of the cylinder upon the inward stroke thereof and preventing flow in the opposite direction upon the outward stroke thereof, a cover member secured to said pump body having a planiform face normal to the axis of said bore and closing the end thereof opposite said inlet passage, an eccentric shaft carried axially within said bore operatively engaging said plungers for movement thereof in 6, one direction and passing through said cover member, and a ring member in sliding engagement with the face of said cover member and in operative engagement with said plungers for movement thereof in the opposite direction.

5. A high pressure pump of the class described comprising a pump body having a central bore adapted at one end to provide an inlet passage for the pump, a plurality of radially disposed bores in said body arranged in circumferentially spaced relation in a plane normal to the axis of said central bore and constituting individual cylinders, corresponding pump plungers reciprocable in said cylinders of a type passing fluid from said inlet to the outer end of the cylinder upon the inward stroke thereof and preventing fiow in the opposite direction upon the outward stroke thereof, a cover member secured to said pump body having a planiform face normal to the axis of said bore and closing the end thereof opposite said inlet passage, an eccentric shaft carried axially within said bore operatively engaging said plungers for movement thereof in one direction and passing through said cover member, and a ring member in full endwise sliding engagement with the face of said cover memher and securing said plungers in respectively fixed relation to said ring.

6. A high pressure pump of the class described comprising a pump body having a central bore adapted at one end to provide an inlet passage for the pump, a plurality of radially disposed bores in said body arranged in circumferentially spaced relation in a plane normal to the axis of said central bore and constituting individual cylinders, corresponding pump plungers reciprocable in said cylinders of a type passing fluid from said inlet to the outer end of the cylinder upon the inward stroke thereof and preventing flow in the opposite direction upon the outward stroke thereof, a cover member secured to said pump body having a planiform fac normal to the axis of said bore and closing the end thereof opposite said inlet passage, an eccentric shaft carried axially within said bore operatively engaging said plungers for movement thereof in one direction and passing through said cover member, a ring member in sliding engagement with the face of said cover member and in operative engagement with said plungers for movement thereof in the opposite direction, a discharge passage from the outer end of each cylinder to a header passage within said body, each of said discharge passages being adapted to receive a check valve unit removably sealed therein to provide for the flow of fluid from the corresponding cylinder into the header passage, and a discharge passage from said header passage outwardly through said body.

7. A pump of the class described comprising a unitary cast housing having a central cored opening therethrough one end of which provides a fluid intake opening, a cover member secured to said housing and closing the other end thereof and having a planiform inner bearing face, a shaft journally carried by said cover and said housing having an eccentric disposed within said opening and to' move in a plane parallel to the inner face of said cover, a series of hollow plungers operatively engaging said shaft eccentric and disposed in a plane parallel to the inner face of said cover and to reciprocate in radially arranged cylinder bores opening outwardly of said housing, valve means within said plungers admitting fluid to said cylinder bores from said intak opening, a ring in sliding engagement with the inner face of said cover and with said plungers and moving therewith in fixed relation to said shaft eccentric, a chamber formed within said housing encircling said cored opening, recesses opening rearwardly of said housing and forwardly into the respective cylinder bores and communicating intermediately with said chamber, valve means disposed within each of said recesses controlling the discharge of fluid therethrough from the cylinder bore into said chamber, and threaded closure members closing the outer ends of the cylinder bores of said housing and said recesses.

8. In a high pressure pump of the class described, a pump housing member having a central chamber opening at on end thereof and a plurality of radially spaced bores arranged in the housing member around said chamber and communicating with the chamber, a closure member removably secured to said housing member at the open end thereof and having a planiform inner face closing said chamber, an eccentric shaft carried by said members within said chamber and projecting through the face of said closure member and normal thereto, a series of plungers reciprocable in corresponding bores within said housing member and disposed in operativ engagement with the shaft and in a plane parallel to the face of said closure member, inlet and outlet ports formed in said housing member and communicating with said bores, and a ring member disposed in the housing member and supported in operative engagement with said plungers by the face of said closure member and disposed to move in sliding engagement with said closure member, the said eccentric shaft effecting movement of the plungers outwardly and said ring member effecting movement of the plungers inwardly with fluid being pumped from the inlet to the outlet ports upon the reciprocation of said plungers.

9. In a high pressure pump of the class described, a pump body having a central bore adapted to receive a crankshaft, a plurality of radiall disposed bores in said body communicating with said central bore and arranged in circumferentially spaced relation in a plane normal to the axis of said central bore and constituting individual cylinders adapted to receive corresponding pump plungers operatively related to said crankshaft, inlet and outlet ports formed in said pump body and communicating with said bores, an end member secured to said pump body having a fiat inner face closing said central bore and extending parallel to said plane normal to the axis of said bore, means in said pump body effecting movement of said plungers outwardly, and a rin slidably supported by the face of said end member in operative engagement with said plungers to move the plungers inwardly with fluid being pumped from the inlet to the outlet ports upon reciprocation of said plungers.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 184,586 Cameron Nov. 21, 1876 1,234,878 Corvin July 31, 1917 2,186,322 Brown Jan. 9, 1940 2,309,551 Trap et a1 Jan. 26, 1943 2,381,910 Joy Aug. 14, 1945 2,382,452 Svenson Aug. 14, 1945 2,461,235 Raymond Feb. 8, 1949 FOREIGN PATENTS Number Country Date 384,386 Great Britain 1932 

